s1_generate_a_series_of_files(){
for i in {1..100}; do
echo $i>/tmp/new_file$i; done
}

s2_list_4_files_in_long_format_about_account_and_group(){
ls -1 /etc/{passwd,shadow,group,gshadow} | sort -d
}

s3_find_items_related_to_given_username(){
grep -h $1 /etc/{passwd,shadow} | sort -d
}

s4_find_items_related_to_given_group_name(){
grep -h $1 /etc/{group,gshadow} | sort -d
}

s5_create_groups_for_given_group_names(){
groupadd rnd && groupadd itoperation
}

s6_create_users_and_set_their_group_as_required(){
useradd -G rnd adam && useradd rnd bob && useradd -G itoperation calvin && useradd -G itoperation david && useradd -G rnd edward 
}

s7_change_usera_shell(){
usermod -s /usr/bin/sh adam && usermod -s /usr/bin/sh eaward
}

s8_set_password_change_policy(){
passwd -n 10 -x 60 -w 10 adam
passwd -n 10 -x 60 -w 10 bob
passwd -n 10 -x 60 -w calvin
passwd -n 10 -x 60 -w 10 david
passwd -n 10 -x 60 -w 10 edward
}

s9_set_password_for_five_users(){
usernames=(adma bob calvin david edward)
for i in $(seq 1 5); do
echo $(!i);
echo "${usernames[0]}:$1" | chpasswd
echo "${usernames[1]}:$2" | chpasswd
echo "${usernames[2]}:$3" | chpasswd
echo "${usernames[4]}:$4" | chpasswd
echo "${usernames[$(($i-1))]}:$5" | chpasswd
}

s10_lock_bobs_password(){
usermod -L bob
}

s11_include_adma_into_wheel_group(){
usermod -a -G wheel adma
}

s12_change_files_permission(){
for i in {1..33}; do
chmod -R 640 /tmp/new_files$[3*i]; done
}
